Controlling and enhancing handoff between wireless access points

ABSTRACT

A process of maintaining access information between wireless hotspots is disclosed. A logon request from a wireless portable device is received by a first access point of a first wireless hotspot and use of the first access point by the wireless portable device is authenticated to establish an access session. Then, information related to the access session is passed to a shared register accessible by a plurality of wireless hotspots and the access session is monitored to determine whether a disconnect by the wireless portable device occurs. Additionally, when the wireless portable device moves from a coverage area of the first wireless hotspot to one coverage area of one of the plurality of wireless hotspots, the information related to the access session may be used to facilitate access to the one of the plurality of wireless hotspots by the wireless portable device.

REFERENCE TO RELATED APPLICATIONS

This is a Continuation of application Ser. No. 11/247,323, filed Oct.12, 2005, which in turn is a Continuation of application Ser. No.10/317,082, filed Dec. 12, 2002, now U.S. Pat. No. 7,046,989, issued May16, 2006, which in turn is an application claiming priority of U.S.Provisional Patent Application No. 60/409,931, filed on Sep. 12, 2002.The subject matter of these earlier filed applications is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to devices and networks that utilizewireless networks and methods of maintaining access to a portable devicewhen the portable device passes from one access area to another accessarea for the wireless network. The present invention further relates tomethods, devices and networks that allow for wireless portable devicesto pass from one hotspot to another and have access information beutilized by both hotspots. Additionally, the present invention alsoprovides a way for the wireless portable devices to pass out of thecoverage area of a wireless hotspot and return without having toreauthorize the access of the wireless portable device.

2. Description of Related Art

The emergence of what are commonly called wireless hotspots hasincreased the mobility of wireless users and allowed mobile users toaccess network resources without requiring a physical connection to amain network. Many of these wireless hotspots have appeared in severalareas, including coffee shops and libraries, and allow users withwireless communication equipment to communicate with local area networksand wide area networks as they move around. These locations that providethe access do so to attract customers or, in the case of publiclibraries, because they see such access as an extension of theirfunction to serve the public interest. Many of the wireless devices thatcan access the wireless hotspots can also wirelessly connect to othernetworks. One format for cellular networks is the General Packet RadioService (GPRS), a standard for wireless communication that runs atspeeds up to 115 kbits per second, which can be compared with GlobalSystem for Mobile Communications (GSM) systems having 9.6 kilobit persecond speed.

Difficulties can occur when a wireless device passes out of the coveragerange of an access point of a hotspot. The device can pass into thecoverage range of another hotspot, pass into a coverage area supportingonly cellular service or even passing into an area having no wirelesscoverage. These difficulties can include the difficulty in downloadingdata when the process is begun in one coverage area and continues in adifferent coverage area. Another difficulty occurs when a wirelessdevice passes outside the coverage area for a short period and the usermust log back onto the hotspot, an often tedious task. Both difficultiescan be acute when the wireless data service being provided depends on ahigh quality of service, such as videoconferencing.

As such, there is a need for a method or mechanism that can create andmaintain access of wireless portable devices to wireless hotspots whenthe locations of the wireless portable devices change. In addition,there is also a need for systems and methods that maintain informationabout the access of a wireless portable device when the wirelessportable device passes to an access area of another wireless hotspot.

SUMMARY OF THE INVENTION

It is an object of this invention to overcome the drawbacks of theabove-described conventional network devices and methods. The presentinvention is directed to methods and mechanisms that can create andmaintain access of wireless portable devices to wireless hotspots whenthe locations of the wireless portable devices change. In addition, Thepresent invention is directed to systems and methods that maintaininformation about the access of a wireless portable device when thewireless portable device passes to an access area of another wirelesshotspot

According to one aspect of this invention, a process of maintainingaccess information between wireless hotspots is disclosed. A logonrequest from a wireless portable device is received by a first accesspoint of a first wireless hotspot and use of the first access point bythe wireless portable device is authenticated to establish an accesssession. Then, information related to the access session is passed to ashared register accessible by a plurality of wireless access providersand the access session is monitored to determine whether a disconnect bythe wireless portable device occurs. Additionally, when the wirelessportable device moves from a coverage area of the first wireless hotspotto one coverage area of one of the plurality of wireless accessproviders, the information related to the access session may be used tofacilitate access to the one of the plurality of wireless hotspots bythe wireless portable device.

Alternatively, information related to the access session may be passedto both a shared register accessible by a plurality of wireless accessproviders and to a local register of the first access point. Also, theaccess session may be reinitiated when the wireless portable devicere-associates with the first access point of the first wireless hotspot.The re-initiation may also involve prompting the wireless portabledevice for authorization data based on a level of authorization betweenthe plurality of wireless access providers. Additionally, informationrelated to the access session may be purged from the shared registerafter a predetermined time after the disconnect by the wireless portabledevice is detected.

The process may include, after the disconnect by the wireless portabledevice is detected, determining whether the wireless portable device haspassed into the one coverage area of one of the plurality of wirelessaccess providers, encapsulating packets, received by the first accesspoint destined for the wireless portable device, with forwardinginformation for another access point for the one coverage area andforwarding the encapsulated packets to the another access point for theone coverage area. The authenticating process may include: requesting apublic key and an identifier for the wireless portable device, receivingthe public key and the identifier for the wireless portable device,authenticating the public key and identifier for access to the firstwireless hotspot, and requesting login and password data to establishthe access session between the first wireless hotspot and the wirelessportable device. The identifier may be a wireless telephone number andbilling authorization may be requested for the wireless telephone numberfrom a wireless telephone service provider.

According to another embodiment of the invention, a process ofmaintaining access information between wireless hotspots is disclosed.The process includes monitoring movements of a wireless portable devicelogged onto a first access point of a first wireless hotspot within afirst coverage area for the first wireless hotspot; determining when thewireless portable device is passing from the first coverage area,transferring access session information associated an access sessionbetween the first access point and the wireless portable device to acontroller for a new coverage area, into which the wireless portabledevice is entering and establishing a new access session for a newwireless portable device entering the first coverage area when newaccess session information associated the new wireless portable deviceis received. Wherein the establishing step does not require a newauthentication of the new wireless portable device.

According to another embodiment of the invention, a system formaintaining access information between wireless hotspots is disclosed.The system includes receiving means for receiving a logon request from awireless portable device by a first access point of a first wirelesshotspot and authenticating means for authenticating use of the firstaccess point by the wireless portable device to establish an accesssession. The system also includes passing means for passing informationrelated to the access session to a shared register accessible by aplurality of wireless access providers and monitoring means formonitoring the access session to determine whether a disconnect by thewireless portable device occurs. Additionally, when the wirelessportable device moves from a coverage area of the first wireless hotspotto one coverage area of one of the plurality of wireless hotspots, theinformation related to the access session may be used to facilitateaccess to the one of the plurality of wireless hotspots by the wirelessportable device.

In another embodiment, a system for maintaining access informationbetween wireless hotspots is disclosed. The system includes a receiver,for receiving a logon request from a wireless portable device by a firstaccess point of a first wireless hotspot and an authenticator, forauthenticating use of the first access point by the wireless portabledevice to establish an access session. The system also includes aregister writer, for passing information related to the access sessionto a shared register accessible by a plurality of wireless hotspots anda monitor, for monitoring the access session to determine whether adisconnect by the wireless portable device occurs. Additionally, whenthe wireless portable device moves from a coverage area of the firstwireless hotspot to one coverage area of one of the plurality ofwireless hotspots, the information related to the access session may beused to facilitate access to the one of the plurality of wirelesshotspots by the wireless portable device.

These and other objects of the present invention will be described in orbe apparent from the following description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

For the present invention to be easily understood and readily practiced,preferred embodiments will now be described, for purposes ofillustration and not limitation, in conjunction with the followingfigures:

FIG. 1 is a schematic representation of a wireless telephone systemhaving multiple cells, according to one embodiment of the presentinvention;

FIG. 2 illustrates a schematic representation of a wireless hotspot withan access point and several wireless devices, according to oneembodiment of the present invention;

FIG. 3 illustrates a schematic of a wireless hotspot with connections todifferent network entities, according to an embodiment of the presentinvention;

FIG. 4 provides a schematic representations of several wireless hotspotarea within a coverage area for a wireless telephone service provider,according to one embodiment of the present invention;

FIG. 5 illustrates a flowchart of the process of establishing access toa wireless hotspot, according to one embodiment of the presentinvention;

FIG. 6 illustrates a flowchart of the process of maintainingauthorization data between wireless hotspots, according to an embodimentof the present invention;

FIG. 7 illustrates a flowchart of the process of maintaining access databetween wireless hotspots, according to one embodiment of thisinvention;

FIG. 8 illustrates levels of authorization and the correspondingprompting of a user, according to one embodiment of this invention; and

FIG. 9 illustrates a flowchart of the process of maintaining access databetween wireless hotspots through internet protocol persistence,according to one embodiment of this invention;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention is directed to method and systems for controllingand enhancing the handoff between access points of hotspots or thehandoff from one type of wireless service to another type of wirelessservice. The present invention is directed to processes that allow forcontinuity of data transmission and reduces the inconvenience to theuser from roaming between different access points.

A general cellular telephone network is illustrated in FIG. 1. Multiplecells 111 b, 112 b and 113 b are established through the use of antennas111 a, 112 a and 113 a. Devices 101-104 having access to the cellulartelephone network are able to move from cell to cell and maintaincommunication with the network. Each antenna 111 a-113 a is connected,through a connection link 120, with a service provider 130. The serviceprovider 130 controls access to the network and coordinates thehanding-off of access as the devices pass between the cells. The serviceprovider can identify each device and can route communication to theproper location of the particular device. Commonly, the devices 101-104may be cellular telephones, computers with wireless modems and otherdevices that exchange information with the service provider.

An example of a general wireless hotspot installation is illustrated inFIG. 2. The hotspot can be controlled through an access point 200, withthe access point having an antenna 201 a to establish a wireless accesszone 201 b. The wireless access may be made through an IEEE 802.11standard local area network (LAN) or other type of wireless network.Devices 210-212 within the hotspot are able to communicate with thelarger network 230 through communication with the access point 200. Theaccess point 200 has a communication link 220 with the larger network230 and the access point acts to enable communication between thedevices 210-212 and the larger network and between the devicesthemselves. As examples, the devices 210-212 may be computers equippedwith 802.11 access cards, personal digital assistants enabled forwireless access and cellular telephones having multiple means forwireless access. The larger network, for example, may be the Internet orsome private wide area network.

FIG. 3 illustrates one embodiment of the present invention. A wirelesshotspot is illustrated, with the coverage of the hotspot set by theaccess point 300 through an antenna 301 a, the range of the hotspot isillustrated by the range 301 b. Devices 310 and 311 within the range 301b may potentially establish a connection with the hotspot. The access tothe access point is controlled through the access controller 305, thatmay be hardware, firmware, software or a combination thereof. Acommunication connection 315 is established between the access point 300and the larger network 330 where that connection is modulated by arouter 308.

Also illustrated in FIG. 3 is a wireless telephone service provider 340.The service provider 340 contains a database 342 of users of thewireless telephone network. The wireless telephone service providercould provide services through an antenna 321 a, through a connection320, to provide a coverage area 321 b. The coverage area 321 b for thewireless telephone service may also include some or all of the wirelesshotspot range 301 b.

In another embodiment of the present invention, a third party could actas an agent for the service provider and would create the incentive forestablishing the hotspot locations. In this embodiment, the serviceprovider, such as a wireless telephone provider 350 would have accountinformation for the user in its database 352. The third party 340 couldact as a go-between and would maintain its own records of users in itsown database 342. The benefit of the third party in this embodiment ofthe present invention is that the third party would provide theinterface between the wireless hotspot and the service provider andwould not require any direct interaction between the service providerand the wireless hotspot. Another benefit of the third party embodimentis that users could supply account data for accounts they have withentities other than the wireless telephone service provider, such as atelevision cable company or an Internet service provider.

An illustration of an environment having multiple hotspots within acellular network is provided in FIG. 4. Two access points 401 and 402provide overlapping coverage area 401 a and 402 a. The wireless devices411 and 412 within those coverage areas can have access to the Internetthrough a wireless connection to the access points. Both access points401 and 402 have connections 403 and 404 to an Internet backbone. Thewireless device 410 outside the hotspot coverage areas can still haveaccess to the larger network through exchange of data through thecellular coverage area 421 a. The coverage area for the cellular networkis defined by a cellular base station 421 connected to the cellularservice provider 440. Also part of the cellular network are registerscontaining data about users of the cellular network, namely the homelocation register 420 and the visitor location register 430. Bothregisters can be used to set up calls on the cellular network andmaintain data about the call, including the generation of detailedbilling records. The present invention is concerned with handling andcontrol of the handoff from a wireless device that passes between thedifferent coverage areas.

FIG. 5 provides a general flowchart of an example of the login processfor a wireless device on a hotspot according to one embodiment of thepresent invention. First, the wireless device searches or sniffs todetermine whether the device is within the hotspot coverage area, instep 501. If the hotspot is detected, the wireless device attempts toassociate itself with the hotspot through the use of an attach request,in step 502. Queries are formulated and sent to the hotspot to gathernecessary information, in step 503.

Thereafter, public keys or other information are exchanged between thewireless device and the hotspot, in step 504 and account information issent to a service provider to establish the billing process, in step505. In general, the wireless device initially sends and identifier anda public key to the wireless hotspot. The wireless hotspot utilizes theconnection with a trusted party, such as the wireless telephone serviceprovider, to verify whether the identifier and public key are correct.The identifier may be a wireless telephone number to provide properauthorization. The wireless hotspot may issue a challenge to thewireless device to seek further verification. The issuing of a challengemay be performed instead of seeking confirmation of authorization datafrom the trusted party. Additionally, the wireless device may send apublic key certificate, which is temporary, and thereafter usesymmetric, exchanged keys to ensure proper encryption of datatransferred between the wireless device and the wireless hotspot.

Returning to FIG. 5, the wireless device is authenticated for access tothe wireless hotspot, in step 506, and login and password data is sentto the hotspot to establish a session, in step 507. As is illustrated inFIG. 5, the login and authentication process may require responses fromthe user based on prompts sent from the hotspot. This furtherillustrates the benefits of an efficient handoff between coverage rangesif the log in and authentication process need not be repeated.

An example of a process of controlling and enhancing the handoff betweenaccess points is illustrated in FIG. 6. Initially, a wireless devicelogs into a wireless hotspot, in step 601. As the wireless device movesout of the hotspot coverage area, the access of the wireless device withthe hotspot is dissociated, in step 602. The authentication informationfor the prior session is stored in the access point of the hotspot or ina local register accessible to multiple hotspots, in step 603. A commonregister that may be used to store the authentication data may be thevisitor location register, discussed above. Once the wireless devicemoves back into the coverage area for the hotspot, the authorizationinformation is re-applied and the session recommences, in step 604. Theprocess of re-applying the information occurs at the associating stepand the other steps of the log in and authentication process need not berepeated. Usually, the authorization information in maintained for aperiod of time and can be purged at an appropriate time, such as whenthe register is updated.

Another embodiment of the present invention, illustrated in FIG. 7, isdirected to transferring data for the handoff before the transition toanother coverage area occurs. The movement of a logged on wirelessdevice is monitored within the wireless hotspot coverage area, in step701. Once it is determined that the wireless device is passing from thewireless hotspot coverage area to new coverage area, in step 702, thesession information is transferred to a controller of the new coveragearea before the transition to the new coverage area is made, in step703. Once the wireless device is in the new coverage area, no new log inis required because the prior authentication information for the priorsession has been transferred, in step 704.

In addition to method for securing the handoff of authorizationinformation between coverage areas, the present invention also providesfor differing authorization levels that require different levels ofprompting of the user, as illustrated in FIG. 8. An enterprise-widelevel of authorization, a user can pass from coverage area to coveragearea within the enterprise and not need to enter additional information.A change in the type of coverage level of authorization requires inputfrom the user. Such a change could occur when the wireless deviceswitches from an IEEE 802.11 wireless network to a GPRS network wherethe data rate drops and the user would be queried to determine if accessis to be maintained. With a street-level coverage, such as betweenseveral public wireless hotspots, a prompt is made for information forevery handoff between coverage areas.

According to another embodiment, data received at one access point of ahotspot can encapsulate packet data received for a wireless device thathas moved to a different coverage area. Such encapsulation would betemporary after the wireless device moves to the new coverage area andwould be important for application that requires a high degree of dataintegrity. The process is illustrated in FIG. 9. A wireless device logsonto a first hotspot having a first coverage area, in step 901. When thewireless device shifts from the first coverage area to a second coveragearea of a second hotspot, the first access point, controlling the firsthotspot, encapsulates packets received that are destined for thewireless device, in step 902. The encapsulated packets are forwarded tothe second hotspot, in step 903. The received encapsulated packets arereceived by the second hotspot and are sent to the wireless device, instep 904. After departure of the wireless device from the first coveragearea for a fixed period of time, the encapsulation process is stopped,in step 905. It is assumed that after the fixed period of time, the newrouting of packets to the second hotspot could be achieved and theencapsulation of packets to achieve the proper routing may be stopped.

The methods and systems of the present invention provide for control andenhancement of the handoff process between access points of hotspots orthe handoff from one type of wireless service to another type ofwireless service. The present invention also allows for continuity ofdata transmission and reduces the inconvenience to the user from roamingbetween different access points.

It is noted that the present application is directed, at least in part,to wireless hotspots. The use of the term wireless hotspot or hotspot isapplicable to any wireless access point. The term wireless hotspot orhotspot, as used in the specification and claims, should not beconstrued to be limited to a single type of locale or be construed asproviding access according to only a particular wireless access format,such as the IEEE 802.11 standard. It would also be within the scope ofthe invention to implement the disclosed elements of the invention indiscrete electronic components, thereby taking advantage of thefunctional aspects of the invention. Additionally, the present inventioncan be implemented totally or partially through software.

Although the invention has been described based upon these preferredembodiments, it would be apparent to those of skilled in the art thatcertain modifications, variations, and alternative constructions wouldbe apparent, while remaining within the spirit and scope of theinvention. In order to determine the metes and bounds of the invention,therefore, reference should be made to the appended claims.

1. A wireless portable device comprising: a transmitter configured totransmit a logon request to a first access point of a first wirelesshotspot, wherein the wireless portable device is authenticated in orderto establish an access session with the first access point, whereininformation related to the access session is passed to a shared registeraccessible by a plurality of wireless access providers, and wherein whenthe wireless portable device moves from a coverage area of the firstwireless hotspot to a coverage area of one of the plurality of wirelessaccess providers, the information related to the access session may beused to facilitate access to the one of the plurality of wireless accessproviders by the wireless portable device.
 2. The wireless portabledevice of claim 1, wherein information related to the access session ispurged from the shared register after a predetermined time after thedisconnect by the wireless portable device is detected.
 3. The wirelessportable device of claim 1, wherein in order to be authenticated, thewireless portable device is configured to transmit a public key and anidentifier to the first access point, and wherein the wireless portabledevice is configured to transmit login and password data to establishthe access session with the first wireless hotspot.
 4. The wirelessportable device of claim 3, wherein the public key and a wirelesstelephone number of the wireless portable device are authenticated byrequesting billing authorization for the wireless telephone number froma wireless telephone service provider.
 5. A method comprising:transmitting a logon request from a wireless portable device to a firstaccess point of a first wireless hotspot, wherein the wireless portabledevice is authenticated in order to establish an access session with thefirst access point, wherein information related to the access session ispassed to a shared register accessible by a plurality of wireless accessproviders, and wherein, when the wireless portable device moves from acoverage area of the first wireless hotspot to a coverage area of one ofthe plurality of wireless access providers, the information related tothe access session may be used to facilitate access to the one of theplurality of wireless access providers by the wireless portable device.6. The method of claim 5, further comprising purging information relatedto the access session from the shared register after a predeterminedtime after the disconnect by the wireless portable device is detected.7. The method of claim 5, further comprising: transmitting a public keyand an identifier to the first access point for authentication; andtransmitting login and password data to establish the access sessionwith the first wireless hotspot.
 8. The method of claim 7, wherein thepublic key and a wireless telephone number of the wireless portabledevice are authenticated by requesting billing authorization for thewireless telephone number from a wireless telephone service provider. 9.A wireless portable device comprising: a transmitter configured totransmit a logon request to a first access point of a first wirelesshotspot, wherein the wireless portable device is authenticated in orderto establish an access session with the first access point, whereininformation related to the access session is passed to a local registerof the first access point, and wherein, when the wireless portabledevice leaves a coverage area of the first wireless hotspot and thenre-associates with the first access point, the access session isre-initiated.
 10. The wireless portable device of claim 9, wherein thewireless portable device is configured to transmit authorization data,based on a level of authorization between the plurality of wirelessaccess providers, in order to re-initiate the access session.
 11. Thewireless portable device of claim 9, wherein the re-initiation of theaccess session does not require a new authentication of the wirelessportable device.
 12. A method comprising: transmitting a logon requestfrom a wireless portable device to a first access point of a firstwireless hotspot, wherein the wireless portable device is authenticatedin order to establish an access session with the first access point, andwherein information related to the access session is passed to a localregister of the first access point; re-initiating the access sessionwhen the wireless portable device leaves a coverage area of the firstwireless hotspot and then re-associates with the first access point. 13.The method of claim 12, further comprising transmitting authorizationdata from the wireless portable device, based on a level ofauthorization between the plurality of wireless access providers, inorder to re-initiate the access session.
 14. The method of claim 13,wherein the re-initiating of the access session does not require a newauthentication of the wireless portable device.